This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project is to investigate partial growth hormone insensitivity (GHI) among children with idiopathic short stature (ISS) and/or born small-for-gestational age (SGA). We propose to integrate functional, biochemical and molecular studies to identify the most reliable markers for children with ISS and/or SGA that have partial GHI in order to put them on appropriate growth hormone treatment (higher growth hormone doses than are given to growth hormone deficient children).